Lapping tool



Nov. 10, 1953 A. SIMONS LAPPING TOOL Filed Sept. 11, 1951 INVENTOR s M 6N3 BY v Patented Nov. 10, 1953 UNITED STATES PATENT OFFICE Claims.

My invention relates to a new and improved tool.

The invention is illustrated in connection with a lapping tool.

A tool of this type can be made and assembled at low cost, and it does very accurate work and automatically fixes the end of the respective lapping operation.

Other objects and features and advantages of my invention are set forth in the annexed description and drawings, which illustrate a preferred embodiment of the invention.

Fig. 1 is an axial longitudinal section, partially in elevation, showing the complete assembled tool, prior to the insertion of the lapping rods into the bore which is to be lapped.

Fig. 2 is an elevation of the lapping rods and their head. The lapping rods are shown as bent out of their initial straight shapes, into their normal selected bent shapes, in which said bent rods are yieldingly maintained by their resilient or springy properties.

Figs. 3 and 4 are respectively sections on the lines 33 and 4-4 of Fig. 1.

Fig. 5 is a transverse cross-section which shows iii the lapping rods in the bore of a wire-drawing die, at the end of a lapping operation.

The half-round rods I and 2 are made of steel or other suitable material. Said rods I and 2 have adjacent and lateral and planar faces I a and 2a. When the planar faces Ia. and 2a of the identical rods I and 2 are in contact, said rods I and 2 form a longitudinal cylinder which has the axis 9.

The head 3 has an outer helical thread 4, a

front longitudinal bore-6 and a rear longitudinal polygonal recess 5.

The rods I and 2 have initial straight shapes. Said rods I and 2 are initially assembled with their lateral planar faces Ia and 2a in full contact along the entire lengths of the identical rods I and 2, up to their front end-walls lb and 2b. The rear end-parts of said straight rods I and 2 are then inserted into bore 6 of head 3, in which said rear end-parts fit closely. Said fit may be a drive fit or any mechanical means may be used to fix said abutting rear end-parts to the longitudinal cylindrical wall of bore 6. At that time, the cylinder which is formed by the initial straight rods I and 2 has the same longitudinal axis 9 as bore 6 and recess 5.

The rods I and 2 are then bent transversely away from each other in front of head 3, to the normal selected bent shapes shown in Fig. 2, in order to form a tool-part T. The bent parts of rods I and 2 are equally transversely inclined to the line 9. If said bent parts are moved towards each other or away from each other from their normal bent positions of Fig. 2, the resilience of said bent parts returns them automatically to their positions of Fig. 2.

This embodiment has a holder I which is operated by hand.

Said holder 1 has a rear end-wall Ia and a longitudinal bore 'Ic.

The rear end-part of bore 'Ic has a thread 8. The front end-part of bore 'Ic has a thread 8a.

The tip It has an axial longitudinal bore I0 Said tip It has a rear extension Illa which has a thread Hid. Tip I0 also has an annular and planer shoulder I00 which is perpendicular to the common longitudinal axis of bore Ia and of the assembled head 3, and a front cylindrical limiting or gauge wall Illb.

Fig. l is substantially to scale. When assembled as shown, bores It and 1c have the same longitudinal axis, which is coincident with axis 9 and the common axis of bore 6 and recess 5.

In order to assemble the parts, the spreadapart bent rods l and 2 are bent transversely towards each other from their positions of Fig. 2', until the tips of said rods I and 2 can be inserted into bore 10 and pushed through holder I. Head 3 is now turned to the stop position shown in Fig. 1 so that the interengaged threads 4 and 8 releasably fix head 3 to holder I. p

The rods I and 2, if released, separate transversely until their rounded outer surfaces engage the front end of bore Ic.

The front ends of rods I and 2 are temporarily held together, until tip I0 is slipped rearwardly upon said front ends. The rear extension Illa is now screwed into thread 8a, until planar transverse shoulder IOc abuts the planar transverse end-wall lb of holder I. The interengaged threads and Iild releasably fix tip II] in the position of Fig. l.

Fig. 3 shows a transverse line which is the trace of a transverse axial plane which is perpendicular to the lateral faces Ia'and 2a. The points [5a and I5b of this transverse line therefore designate the laterally outermost longitudinal lines of the rounded or semi-cylindrical outer surfaces of rods I and 2.

In the assembled tool of Fig. 1, said rounded surfaces of rods I and 2 abut the longitudinal cylindrical limit wall lb of tip I0. Said limit wall IOb is coaxial with bores I01, 10, 6 and recess 5. There is then a selected transverse distance between the planar faces Ia and 2a, and another 3 selected transverse distance between the longi tudinal lines which are represented by points IIa and lib.

A wire-drawing die B or other article has a bore I6 which is to be lapped. Said bore I6 has circular cross-sectional lines, one of which is shown in Fig. 5.

The original diameter of bore I6, or of the part of bore I6 which is to be lapped, is less than e diameter or the cvi n c l miting wall n The front operating end-portions of mm I and 2, which are located in front of the tip III, are therefore forced transversely towards each other, in order to insert said front operating end; portions into bore I6, at the start of the respective lapping operation. At said start,1thm are equal clearances between the rounded surfaces of rods I and 2 and limiting wall IIlb.

As the lapping continues, bore I6 is enlarged, until rods I and 2 abut: limiting wall IIIb, thus automatically stopping further enlargement. of bore It The. wall lab thus acts as an automatic e. e tip Ill. may be r p aced by another tip, which has. a limiting or gauge wall lb of different diameter than the initial wall I b.

I have described a preferred embodiment of my invention, but numerous changes, and sinus and additions and substitutions. can be. made without departing from the scope. The invention also includes. the sn combinations, and parts oi he omplete tool.

Thus, the rods I, and 2. instead of being halves of a, cylinder, can be. halves. of a frusto-cone, in which the, frusto-oQn-ical shape may be, of greater m st at its rear end than at its front end. In such cas the rods I nd 2 can be longitudinally relative to holder 1 and tip. I0, so that the transverse spacing between the front-end portion of rods I; and 2 can be. adjusted as desired. In such case. the wall lib can'be either cylindrical r of n p l ona shape. or it may be frusto-rconical. The. important feature is to have. only a line contact or point contact between the wall lb and; the rounded portions. of rods I and 2.

I own;-

1. A lapping tool which c mprises a hollow holder- Wliicl-r a. longitudinal holder-bore and e (rout end and a rear and. a hollow tip which has a longitudinal tip-bore which is alined with said holder-bo a plurality f: lappingm mbers which extend through, said holder-bore. and said tip-bore and which also extendforwardly of said tip, said lapping members fixed to. said 1 914. in said holder-borerearwar l x ofthefront end ofsaid holder-bore said. tiphaving a, longi-v tndinal gauge-well, said. lapping members being yihldmglvbiased transverselyaway from; a h other against said gauge-wall. said lapping membersb ing movable towards each other away from said gauge wall.

2. A. apping tool. ac o di g to claim 1: which said leaping members are bendable. and r silient an are; thus biased by their resilience.

3. A lapping tool according to claim 1 in which there are two substantially identical half-cylindrical lapping members which have lateral planar faces, said lapping members being bent out of normal straight and abutting shapes to normal transversely divergent shapes, said lapping members being bendable and resilient and being biased towards said normal divergent shapes by their resilience.

A l m a tool w ich has a lmisitwimal'axia. said tool comprising a plurality of longitudinally disposed lapping members which are flexible and resilient in a direction transverse to said longitudinal axis, said lapping members having original straight shapes, said lapping members having operating front end-portions and nononemting and holdin r a nd-p rti s. h lding-means which hold said rear end-portions in fixed relation to each other, said front end-portions being bent out of their original straight shapes to normal bent shapes said front mdportions diverging transversely from each other in a normal angle. of divergence in said normal bent shapes and being biased by their resilience to yieldingly maintain said front end-portions in said normal bentshapes, and supplemental means which hold front end-portions in divergent relation and with an intermediate angle of; divergence which is less; than said normal angle of divergence.

5. A lapping tool whichhas a longitudinal, axis. said tool comprising a plurality of longitudinally disposed lapping members which are, flexible. and resilient in. a direction transv rse. to said longitudinal axis, said lap ing members having ori ia trai t shap s. said lapping members having operating front end-portions and non-operating and holding rear end-portions. holdingmeans which hold saidrear end-portions in fixed relation to each other, said front end-portions being bent out of their original straight shapes to normal bent shapes, said front end-portions divirging transversely from each other in a normal angleof divergence in said normal bent shapes and being biased by their resilience to yieldingly maintain said front end-portions in said normal bent'shapcs, and supplemental means which hold tront end-p rtions in divergent, relaion and with. an intermediate angle of diverg ce which is less'than said normal angle at di r nce. each said front end-po n. ing permanently bent transversely away from said axis relative to. the respective rear end-portion ABRAHAM SIMONE.

Belcrences. Cited in the file of this patent UNITED STATES PATENTS Number Namev Datev .1 3, cowing Apr. 14,, 18.63 1,562,327 Hedeen Nov. 17, 1925 1,939,482 Aurili Dec. 12,, 1933 2,014,177 Graul Mar. 16., 19,37v 2.19.6932 Roberts. Apr. 9.. 1940 

